Production of artificial materials



H. DREYFUSY PRODUCTION' 0F ARTIFICIAL MATERIALS Filed may a, A:w40

S u uw. a 8 C r M o H V. M W Mu a 3 4 QT. d m Q/o/ N x E lla llllnllll llllll Vl l- I 2 3 2 M f I 4 2 9 3 a //,//V//// substance,

Patented Dec.` v1,` 1942 A.UNITED sTATEs PATENT ortica.

rRopUc'rIoN oF ARTIFICIAL MATEnTAps Henry Dreyfus, London, England, assigner to Celanese lCorporation of America, a corporation of Delaware Application May isiaseriai No. 333,952 l 3 Claims.

This invention relates to thel production of artificial filaments, threads, foils, films and similar shaped articles.

` According to the invention, artificial filaments,

threads, foiis, lms and similar shaped articlesl may be formed by extruding a fusible, ibre-` or nlm-forming substance or a composition containing the same, while in a fused lor plastic condition, through orifices of appropriate shape under pressure applied' directly to the materials byan inert liquid or vapour, and settingithe extruded materials.

Pressure may be -applieddirectly to the fused or plastic materials by means of water or a large number of other liquid agents, especiallyl highboiling liquids. Thus, alcohols and ethers, e. g. ethyl, nand i-propyl, andi-amyl alcohols and the corresponding vsymmetrical ethers, the dimethyl ether of triethylene glycol, anisol, the dinaphthyl Vethersand diphenyl etherpor hydrocarbons, e. g. petroleum ether, kerosene, benzene,

toluene, acenaphthene,` naphthalene andits alkyl and phenyl derivatives, phenanthrene, and partially or fullyhydrogenated aromatic hydrocarbons, e. g. tetralin, may be employed. Halogen substitution derivatives may also serve asV agents. While the agents employed are preferably such as are fluid at ordinary temperatures or at moderately elevated temperatures, e. g. temperatures of 50 or 70 C. up to 10G-110 C., there may be I employed other agents which become fluid-at a temperaturebelow the extrusion temperature of the materials, such as, for example, anthracene and its alkyl and aryl derivatives, and the dinaphthyls. The actual liquid employed will de- .pend upon the temperature conditions and upon 'f the characteristics of the substance orsubstances present in the materials. Alternatively, pressure may be applied directlyto the fused orplasticv materials by an inert vapour such as, for example, steam, or the vapour of a member of the groups of organic liquid agents specified above.

The present invention is particularly'applicable to the production offllamentary articles, especiallysuch as have a basis of a thermoplastic llilamentary articles maybe vproduced by extruding the fused or plastic materials y through orifices and continuously collectingthe extruded materials on rotating drums or the like,

preferably at la rate in excess of that at which 5o they emerge fromthe orifices. so that draw-down is applied while they are still in a more or less fluid or plastic condition. Preferably the materials are extruded' whileV at elevated temperature,

through the hollow shaft I8 and adapted to gen- May is, 1939 `for example, the materials may be heated electrically or byzmeans of a steamcoil. V'l'he inert liquid or vapour by meansof whlchpressure is to be applied for extrusion is preferably maintained at a temperature at least as high as that of the materialsand thewlatter may themselves be heated by passing hot inert liquidor vapour through a powdered, granular or fused mass of the ma.- terials. When-the fused or plastic materials are employed at elevated temperatures it is advantageous to make provision for heating the orices so that thetemperature of the materials is maintained up to the instant.` at which they leave the orifices.

An apparatus whichcan be employed for forming filaments from hot fused or plastic materials according to the invention is shown by way of example in the acc mpanying drawing.

A cast-iron'or steel vessel I, adapted to withstand high pressure, carries six narrow-tubular ,elements 2 vertically projecting from its base,

each carrying fine metal gauze 3 and dished plates l suitably drilled to serve as spinnerets, retained by nuts la., The yhead 5 `of the vessel is removable for cleaning purposes, being clamped to the bodyof the vessel by bolts 6 operating in opposing flanges 'I andA 8. The head carriestwo tubes Sand I0, the former being lagged, equipped withstop valves,v I IV and I2 to allow for introducing and withdrawing liquids and/or vapours, a pressure gauge I3, and a device Il Afor controlling the internal temperature of the vessel as indicated below. A stirrer I5 mounted in the vessel to rotate in the bearings I6 and I1, the latter providedwith 'a stuffing box, comprises a hollow shaft I8 carrying stirrer armsil anda conveyor screw 20, and is `driven by gears not shown, so

that on rotation the conveyor screw tends to' cause liquid in which it is immersed to rise. Although not so illustrated, thestirrei` arms are preferably not disposed in a vertical plane but are sloped so that on rotation they tend to cause liquid toy fall. The stirrer arms are wound with coils 2l supplied with alternating current by leads erate heat by power losses in the stirrer arms and the lower portion of the shaft. The current flowing in the coils is controlled thermostatically' by the device I4.

Lagging 22 is provided over the whole surface of the vessel, including the head, to reduce heat vlosses from the vessel, Aand electrical heating lwires are provided in the lagging on the body of whether or not the temperature employed is suf- 55 thea,l l'vessel to allowv for heating the contents.

i of these.

Further separately controlled electrical heating v coils are provided in lagging 23 which surrounds the projecting tubular elements 2 and extends below the level of the plates 4 by an amount approximately equal to the diameter of the coils,

so that the face of the plates may be heated.

In operation, according to a preferredA method, the vessel is filled with a high boilingpetroleum hydrocarbon, which is' brought by. the passage of current through the electrical heating wires in the lagging 22 to the temperature at which it is desired to extrude the fused or plastic materials. The current is then switched'off from this circuit and that to the coils 2| and those in the lagging 23 switched on, and power is applied to the stirrer so as to rotate it at a slow rate, e. g., 1 to 2 rotations per minute.v 'I'he current necessary to maintain the face of the'plates 4 at the desired temperature can be determined by simple experiment, being adjusted to give satisface tory spinning. From another vessel, not shown, preffused materials are fed through thel pipe 9 into the vessel, hydrocarbon being simultaneous' ly forced out through the pipe 10 until the materials, which sink to the bottom ofthe vessel, .fill it to about S of its volume. 'I'he'valve` I2 f is then closed yand a suitable pressure developed through a reservoir of hydrocarbon communicat- .ing with the vessel through the pipe l sothat the fused materials arefextruded through the spinningjoriflces.

I As required, further fused materials may be introducedinto thevessel through the Apipe 9, hydrocarbon being 'allowed to flow off through the pipe l0, if necessary. It is desirable to ensure that the level of. fused materials.

in the vessel does not vary to vany great extent during'spinning, so that `uniform resultsmay be obtained. 'Y j' 4If desired, electrical heating elements may be r placed inside the vessel and the stirrer dispensed l with, or alternatively, reliance may be placed on external wiring for all heat'generation.

yInstead of providing externally projecting'tubular elements to carry the spinnerets, similar elements projecting inwards from the base ofthe vessel may be provided, vand 'the plates carrying the spinning orifices mounted at the upper ends This construction avoids the need for wiring lthe tubular elements. The tubular elements, whether projecting outwards 'or' inwards, mayihave a diameter of lv inch or less,- e. g., l/s or 1/4 of anlinch upto 2 or 3 inches. j

While in" the above description, reference has i been made to heating the contents of the vessel by electrical heating coils, -it is to be understood "that other heating means may beemployed. For

example, the vessel may besurrounded by a jacket through which hot4 oil or other theating uid maybe circulated so as to provide the necessary heat.

If extrusion is to be effected under the pres- 195 C. However, higher temperatures, e. g., up to 250 or 300 C. o r more, may be employed, depending inter alia upon the nature of the materials andthe size of the orices.

'I'he extruded materials are preferably received, directly after leaving the extrusion orifices, in a gaseous or vaporous medium having such a composition, and maintained at such a temperature and pressure that any'tendency to rapid change in the composition'or physical state of the mate--y rials is reduced. For example, fused cellulose acetate` extruded under pressure may be received in anl atmosphere of wet steam maintained at a temperature yof the order of 120-130 C. or

`more. -Setting of thematerials may ybe veifvzct'ed or, if already commenced'in the said gaseous or vaporous medium, may be completed by introdillm.

ducing 'them` into a cool liquid non-solvent meabout a vrapid and, preferably, considerable tem- 'v perature drop, e. g.. of the order of 100-I200 C., or more, in the extruded materials shortly after they emerge from the orifices. Thus the fused or plastic materials may be extruded intoa -gaseous or .vaporous medium as described above, and'the'extruded materials vbe led after a short f travel in that medium,e.. g., a travel correspond?.

` ing to a time of 0.050.1 or 0.2'5 second, into a relatively cold liquid medium which, acts as a setting 'medium Such a liquid rmedium may consist wholly of non-solvent for the fibre.. or film-forming substanceor it may contain a proportion of a solvent or softening agent therefor.

Forexampla when'anv acetic acid ester of cellulose or a composition having a basis ofsuch an ester is extruded, it may be set by introduction into Ia relatively cool aqueous solution, of diacetone alcohol, diethyl tartrate or ethyl lactate,

preferably in a concentration of -65%. It may be desirable, according to the tenacity, extension and pliability desired .in they products'to ,employ a medium *whichf will withdraw .part or all of any `plasticiser which may be present in thematerials. Thus, anextrudedcomposition comprising cellulose: acetate and a .highV proportion of v dimethyl phthalatem'ay befpassed into aqueous alcohol. Compositions A containing phenols or other,l acidic softening agents may be set fin a dilute aqueoussolution-of `caustic soda, provided` that the :solution-does not have an undesired -effectupon other components of the composition.

Salts,4e. g. sodium chloride and calcium chloride, -may be 'dissolved in the setting medium.

Alternatively, a gaseous ory vaporous medium,

' e. g., air or steam, which is preferably circulated underconditions which `permit strict control of its temperature, may :be employed for setting purposes in place of the above-mentioned liquid Asure of an inertv liquid andthe materials are to y 'be heated to a temperature above the 'normal -boillng point of that liquid, this temperature Awill determine the minimum pressure `Within the vesseland this pressurey may be sufficient to may be applied through the liquid to assist in extruding the composition. Total pressures may range from 5 atmospheres or less up to 40 or 50 atmospheres or even more. For example, presff t extru 'on. However, additional ressurel l e ec s1 p Istance. Suitable plasticisersiforicellulose acetate Anon-solvent medium. 4Such a medium may be maintained at super-normal, normal, or sub-normal pressure.

The fused or plastic materials may consist whollyof one or more fusible flbre-y or film-forming substances. In general, however, it is preferablek` to employ compositions which contain plasticisers for the iibreor film-forming suband like compositions are, for example,di'-and tri-acetin, f tri-phenyl-acetin, phenols, tri-cresyl phosphate, dialkyl, phthalates, dibutyl tartrate and Vthe,v sulphonamides, e. g., p-toluene sulphonamide. Phenols, especiallyi high boiling phenols,'e. g., resorcinol y'and diphenylol propane, acetamide, `methyl formamide, adipamide, benzamide, ysulphonaltuides,e. gimp-toluene -sul- Advantageously, this ymedium brings` i ifni `bef garten asfttereirb'yithtermftplestidiserf' ifrideitpolyvinybechlon-aoetateeandisonolvrnersgof I til' sclifcfiripsitinsri [wilhelm vinyl acetate and' vinyl chloride, polymenised Pistfcisersfiirayibe'renipioteoimproportionsfdf esters :efuunsammtedi-acidspiemgmtnqse erettile iupt-Y'tfcr MQSMHJ eviilinb'ie based! fh acryliclyanoniethacryli voelde; Series., finiti-9mm ightl-o'lfthef-fiibrforimmefdtiingflsuli- 10 idilmrformiunolyamidesi img55;,theprarinatag,oh-` s'tncaffiwptiru iariilsiitamewhpcsimnmav-ci itainedrhesconseusatiommf dilemmes giuridica:- fiirgiaiesrso'f anoscetivaciairestexttrieenuloseiis miieffbccntatningu about ousssomuobmmmetnyi @ons aminpeamboxylim omaminersulehoaic phthalate or other plastieiseiumrhi compositions acidsbanc othemiibree oralllmeiorminsnmivaiex 'Smssriasfedntamitnenagentsa'order:toimdify -1 uohtainabieienrmndenaetionat iii-imboccare- 4I )IOpelties GWW-Wiliam@ eileiisffil me li ,ml-limi used -avnli ritiriw gist sin 'msm-lm -prcidiretstii'mney mayacfontaimtroniemnple. nigh qe' 'Imeoshspedrartielesfmsr subieciedato, hoiiig "soventsb1pigmeiits,edys.fdndi/fj miefcrestddntg, nfribmxe admiramos loiriuf .aelni'i tviewatmxnodifyinxr theinicheraoteristiesmiio. te!

lenistribatlm of miasticisezsaandenthemagents gorampleitbsya maritime @nstretcllilisl eth'otgimlit the wil'fllsitlons'ishouldrl-:biw urii- 052 weitmlllebfl'almint nrlilvahtlrekn moesen mtmmbeeeaeeteduiorsek rstretcloebeIcue/settineanciemssuehia stretcb iaimleebyntneafmmembre-rronimaiomuus ,sestopsrstioleaevlieoieitereeettiae 'incentratesubstance with a solution or dispersionaiil'raeicolas-v y' grigls m betreatgmthgfsoigtening agptrgg.. -tienesnaenenaomaterqrainmhstaneer es: e., 25 a soiuppaqnamvgptmnlastidesmrra saluent sauer.` met@ weuemmdsllwmmheee gteeaeseaezssoaenenm .sefteasd einem #substance @tithe-wwwmain@ www1- fi entretenant atlas eieessreeelfalth. mdmmideve'rswuwthewnmlteeebemetemere! v.i .met beenafeitar-adolescenten@ .1.1- sonintraprenderefassdescribeufiin,@narines.existait` ..1 ggfsesgggq smiling-typing, l 1-`"L roxy einnnseapgolieationi Seriaiqiloieffisiil; iiledniMay 35 Thus they may randagi-'1m emat- .eaeimrae i@ mae am enges se while immersed in ot atr or whiieina steam omnothemanthodibycwiiichctheiragentaanagy che eehanifberic Iritliis prodcuniormly rdistributedzeonlmiaes etreatingsithe, andtainiayibe stiliifnetheir nicreasedieJLted-ocieea :l

enbrearo'xenlmeiormingcsubstancecwitbratsolution f es niternatiuelneoxeamadditiqnnihenrticlesfmay or dispersion of the agents irisareuokailaihlelt loabeisilbibeiedi'mhietriumf,iafishl'inknet' foithe'ilbtn'ciion by adding the agents to ace neas g3 olutiqnusnera nuisent-cion menilbxecnor solution of the substance in a volatile solvent. nlm-forming substance,inthe absence of stretch- In the former case the materials are worked, e. g., ing tension so as further to modify their propby malaxation, until the substance is dissolved. erties.-

When a uniform solution and/or dispersion of 4;, Again, shaped articles having a basis of nbrethe components has been obtained, the volatile solvent may be evaporated, either wholly or in part, so as to leave the required composition.

The plasticisers and other agents may also be of cellulose derivatives containing -free hydroxyl groups, may be esteriiied. For example, shaped dispersed throughout the breor nlm-forming 5u cellulose derivative articles may have.their irony ing point substantially raised by esterifying them substance byheating the latter under an rinert liquid which is to be used to apply pressure to the c fused or plastic composition and which is preferably without substantial solvent action on lthe with halides of polycarboxylic'acids, e. g.. adipyl, phthalyl, oxalyl, succinyl or thionyl chloride,

.manie @mnemonic instemmen-condense ,v

.nusttreatmenta haveibeemsetnrritb or nlm-forming substances containing tree hydroxyl groups, particularly such as have a basis and/or jwith the corresponding` anhydrides, for

plasticisers or other agents, and then introducing 5;, exampleas described in U. S. applications. No. ,n

the agents in nely divided form anddispersing .them with the substance in the body of inert liquid, preferably .with vigorous stirring. The fication and improvement of the productsmay dispersion, which should be suiciently coarse to be secured by treatment according to the process ensure rapid settling, is then allowed to settle, 60 describedin U. S.- application S. No. 355,376, flied preferably in a separate heated closed vessel, and the intimate mixture of substance and agents is then in condition for extrusion under pressure forming shaped articles according to the process transmitted through the inert liquid. of the invention and subsequently esterifying Particular reference has been made above to 65 them to increase theirl ironing point renders it acetic acid esters of cellulose as lthe flbreor fllmpossible to spin products from substances having forming substance suitable for the production melting points which are undesirably low for of shaped varticles according to the invention. textile purposes but which are advantageous in Among such .esters may be mentioned cellulosel g acetate, aceto-propionate, aceto-butyrate, and 70 mined by the melting DOD, may be lower. aceto-stearate. However, the process of the in- Filamentary products produced according to vention is applicable to a large range of other the invention may be associated together, e. g., fusible breor film-forming substances, such by twisting, to form yarns and they may then as, for example, other cellulose derivatives, e. g., be employed in the manufacture of woven,knitted cellulose propionate, butyrate, stearate and 75, or other fabrics. Filaments of relatively high 306,704; tiled November 29, 1939, U. S. application plication No. `26,05'7/39. 'I'he combination of S. No. 344,460, filed July 8, 1940. Further modi- September 4, 1940, corresponding to British ap` that the spinning temperature, which is deter-v 4 t denier may be employed directly as artificial vhorse-hair or bristles. The filamentary products may also be coalesced underthe influence vof'solvents, plasticisers. and/or heat. to form unitary products suitable for use as bristles or the like. f

For the production of fibres according to the invention, i'ilarnentary products produced as described above may be cut after winding or while travelling', e, g., by 'the methods 'described in U. S. application B. No. 155,949, filed July 27.

1937 i U. B. Patents N0s.i2,079,094 and. 2,010,078;

and British Patents Nos. 357,555 and 317,025.

Such fibres are preferably products from ills.- mentary materials which have been crimped, e. g.. rby twisting as yarns, setting the twist by Asteaming or similar treatment, and untwisting.

Alternatively or in addition the cut nbres may be vcrinlrled by treatment with a solution of a solvent or swelling agent as described, for example.' in U. S. applications S. Nos.` 306,904,A filedv November 30, 1939; 319,076, filed February' 15,

fibres so producedrnay be spun into yarn;` e

Films, foils and ,the like produced according to the invention mayV be employed for many of the purposes to which cellulose acetate or similar artificial films, foils and the like have previously been applied. For example, they may .be employed for wrapping purposes, askbases for carrying photographic emulsions, as glass substitutes', and for the manufacture of splinterless glass.

Example A composition comprising-85% of cellulose aceto-butyrate (acetyl value 12.9%, vcalculated as acetic acid; butyryl value 54.4%, calculated as butyric acid) and of dimethyl phthalate is fused under kerosene by heating to 185 C. and

v1490; and 318,709, filed February 13, 1940.@-The fed into a vessel as shown in the accompanying drawing. the vessel lbeing previously filled with kerosene and brought to lii4 C. A pressure of 200 lbs/sq. in.: is applied through a reservoir of hot kerosene and the fused cellulose acetate ccmposition is extruded through the spinning orifices into; a' chamber containing wet steam at 1259 O. through which the extruded materiels pass in a time L0110.1 second, and-.thence into abath of water maintained at 25 C; The extruded maierials are continuously withdrawn from the bath 'and wound up so as to draw them down during travel from the orifices. l Having described my invention, what I desire to secure -by Letters Patent is: l

1. Processv for the production of artificial filaments, threads, foils, films and similar shaped articles, which comprises extruding a fusible liber-forming substance, while in a fused or plas` tic' condition,v through orifices of appropriate Ashape under pressure applied directly to the material by an inert liquid and setting 'the extruded materials. f 1

2. Process for'the production of artificial fila-U ments, threads, foils, films and similar shaped articles, which comprises extruding a fusibleorganic derivative of celulose, while in a fused or plastic condition, through oricesrof'appropriate shape under pressure applied directly to the material by an inert liquid and setting the extruded materials. w y

3. Process for the production of artificial filamentsjthreads, foils', films vand similar shaped articles, which 'comprises extruding a 'fusible acetic acid ester of cellulose, while in ya. fused or`plasti'c condition, through orifices of appropriate shape under pressure applied directly to vthe material by aninert liquid and setting the extruded materials.

HENRY DREYFUS.

. ....1 v.\ rh. 

